Chemistry
Roozbeh Behzadi
Abstract
The removal of sulfur compounds in hydrocarbon fuels is important from an environmental point of view, because in the combustion process of fuels in engines, sulfur compounds in the fuel are converted into sulfur oxides (SoX), which will cause the problem of acid rain. In addition, (SoX) resulting from ...
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The removal of sulfur compounds in hydrocarbon fuels is important from an environmental point of view, because in the combustion process of fuels in engines, sulfur compounds in the fuel are converted into sulfur oxides (SoX), which will cause the problem of acid rain. In addition, (SoX) resulting from the combustion of sulfur-containing fuels in internal combustion engines, while causing corrosion in the internal parts of the engine, causes poisoning of the catalytic converters installed in the exhaust of cars, and finally causes the deactivation of these catalytic converters in a short period. An important plan of these catalytic converters is to reduce the emission of nitrogen oxides into the environment. Likewise, sulfur oxides lead to the rapid deactivation of the filters installed in the exhaust to prevent the release of suspended particles into the atmosphere. Therefore, the presence of sulfur compounds in hydrocarbon fractions, in addition to cause problems related to the release of sulfur oxides into the atmosphere, leads to the aggravation of the problem of the release of pollutants such as nitrogen oxides and suspended particles into the environment.
Engineering
Mohadeseh Aliakbari
Abstract
This study examines the definition of organizational knowledge in industrial and commercial companies. Knowledge in an organization is knowing the reality or situation of something, however awareness and understanding that have been obtained through experience, study, exploration and mental communication ...
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This study examines the definition of organizational knowledge in industrial and commercial companies. Knowledge in an organization is knowing the reality or situation of something, however awareness and understanding that have been obtained through experience, study, exploration and mental communication and have been recorded in various forms and the purpose of knowledge management is to identify, acquire and organize and Appropriate storage and transfer of knowledge in order to improve and change the perceptions and performance of employees at different levels of the organization at the appropriate time, which prevents the outflow of intellectual and mental assets from the organization when leaving knowledge agents. Knowledge management consists of various elements such as knowledge production, knowledge acquisition, knowledge storage and transfer and sharing. However, it can be said that knowledge transfer is the movement, distribution and dissemination of knowledge between individuals and mechanized and non-mechanized knowledge bases. In two ways, for which two types of strategies are conceivable, the strategy of person-to-document transfer and the strategy of person-to-person transfer. The role of human resources training and development professionals in the management and knowledge transfer process is critical. These maps can be created through various activities. In fact, education management and human resource development can address the shortage of information and knowledge in a timely manner and lead to the horizontal growth of people in jobs by resorting to knowledge management system along with other resources to meet educational needs.
Hormooz Asadi Kohbad; Hasan Bahramipor Naghani
Abstract
Damage does not follow a person's fault enough to establish a causal relationship, but it must be proven that the fault is the actual cause and cause of the damage and without it the damage would not have occurred. The meaning of because here is not the complete cause or the perfect cause, but the cause ...
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Damage does not follow a person's fault enough to establish a causal relationship, but it must be proven that the fault is the actual cause and cause of the damage and without it the damage would not have occurred. The meaning of because here is not the complete cause or the perfect cause, but the cause and the factor that the damage is documented in his action and the custom attributes to him. Recognizing the existence of a causal relationship is not always easy because different factors may have been involved in causing the damage. It is not possible to say exactly which one was the cause. In cases where several people are involved in causing damage, some of whom are guilty and some are not guilty, the custom attributes the damage to the person who was at fault, but if all the factors influencing the damage are to blame, it is difficult to identify the cause and establish the cause. Assuming someone is injured in an accident and dies in hospital, a number of factors may play a role in death: a car crash, delays in first aid, the incompetence of the surgeon's illegitimate surgeon, who overtakes him beyond legal hours. As a result, the victim left the workplace later than usual and crashed into a car that was passing by at the scene at that time. To answer the question of which one should be considered the real cause of the damage, four opinions were raised.
Physics
M.I. Anthony; O.O. Ige; U Rilwan; O.A. Folasanya; A.A. Muhammed; N.U. Angela; Atef El-Taher
Abstract
In this work, the neutron-induced fissile isotopes of Uranium-235 using the Coupled-Channelled Optical Model code (OPTMAN) code up to 20 MeV. The high demand for nuclear reactor fuels has necessitated this research. As one of the major naturally occurring radionuclides with lots of fuel prospect, Uranium-235 ...
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In this work, the neutron-induced fissile isotopes of Uranium-235 using the Coupled-Channelled Optical Model code (OPTMAN) code up to 20 MeV. The high demand for nuclear reactor fuels has necessitated this research. As one of the major naturally occurring radionuclides with lots of fuel prospect, Uranium-235 occur in 0.71%. Two steps process away from Uranium-235 of neutron capture can produce fissile materials to be used as reactor fuel. Though, Uranium-235 is not with them self a fissile material, but they are breeder reactor fuels. Computations were done for both the Potential Expanded by Derivatives (PED) which account for the Rigid-Rotor Model (RRM) that treat nuclei as rigid vibrating sphere as well as account for nuclear volume conservation and Rotational Model Potentials (RMP) which account for the Soft-Rotator Model (SRM) that treat nuclei as soft rotating spherical deformed shapes. Each of the calculated data was compared with the retrieved data from the Evaluated Nuclear Dada File (ENDF) which was found to be in good agreement. The threshold energies in all cases were found to be ≤ 4 MeV for both PED (Potential Expanded by Derivatives) and RMP (Rotational Model Potentials). It is observed that results from RMP much better agreed with the retrieved data than the one obtained from PED.
Hormooz Asadi Kohbad; Hasan Bahramipor Naghani
Abstract
One of the most important rules of jurisprudence that causes coercive guarantee is the rule of Ali al-Aid, which is known by famous jurists, both Shiites and Sunnis, as narrated from the Prophet. Among the Shiite narration societies, this narration has been quoted in the book Mustadrak al-La'ali, quoting ...
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One of the most important rules of jurisprudence that causes coercive guarantee is the rule of Ali al-Aid, which is known by famous jurists, both Shiites and Sunnis, as narrated from the Prophet. Among the Shiite narration societies, this narration has been quoted in the book Mustadrak al-La'ali, quoting the commentary of Abu al-Futuh al-Razi and Awali al-Lali al-'Aziziyya, as follows: It's going to take what it takes until it returns. Ibn Abi al-Jumhur al-Ehsa'i has narrated this narration in three cases in his book Awali al-Laali al-Aziziyah. In the first case, he has quoted it without specifying the name of the Prophet, and in the second case, by specifying the name of the Prophet, but in the first way, without mentioning the intermediary, and in the third case, he has quoted it from the Prophet through Samra. There is a difference of opinion among jurists in explaining and interpreting the provisions of this rule. In examining the provisions of this rule, the question arises whether the provisions of the rule are an obligatory ruling on the necessity of rejecting other people's property, or the guarantee and responsibility of a person in charge of other people's property?
Engineering
Ali Rezaei
Abstract
Schizophrenia has existed throughout history, as ancient Greek physicians have described it with different symptoms, but it was not seriously studied until the second half of the nineteenth century, and from the second half of the nineteenth century the classifications related to Schizophrenia developed, ...
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Schizophrenia has existed throughout history, as ancient Greek physicians have described it with different symptoms, but it was not seriously studied until the second half of the nineteenth century, and from the second half of the nineteenth century the classifications related to Schizophrenia developed, which of course was very personal and tasteful. Arnold pick was the first to use the term Dementia praecox to describe the apparently Hebephrenic type of psychiatric disorder. Schizophrenia is a mental disorder characterized by persistent or recurrent forms of psychosis. The main symptoms include hallucinations, delusions, and disordered thinking. Schizophrenia is a chronic and severe brain disease that affects a person's thoughts, feelings, and behaviors, as well as impairing a person's realism. The onset of the disease is between the ages of 16 and 30, but in rare cases it is also seen in childhood. The prevalence is equal in men and women, but the onset age is earlier in men than women. The age of onset in women is two peaks. The age of onset is 10 to 25 years for men and 25 to 35 years for women. The onset of the disease before the age of 10 and after the age of 60 is rare. In cases that start after the age of 45, it is called schizophrenia with a late onset.
Engineering
Peyman Vaziri
Abstract
Design, supply and drilling (EPD) contracts, referred to in the downstream industry as turnkey contracts, are new contracts in the drilling industry that can be attractive to both employer and contractor. In this type of contracts, the design, supply of equipment and goods, as well as drilling wells ...
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Design, supply and drilling (EPD) contracts, referred to in the downstream industry as turnkey contracts, are new contracts in the drilling industry that can be attractive to both employer and contractor. In this type of contracts, the design, supply of equipment and goods, as well as drilling wells are the responsibility of the drilling contractor. Therefore, all risks in all three stages are the responsibility of the contractor and in this regard, these contracts are attractive to employers. Therefore, by managing and allocating new risk by placing conditions and clauses, these contracts can be replaced by the format of previous contracts. Studies and researches in the field of EPD contracts in the world and Iran in the field of production wells have been done, also projects in this field have been done in South Pars field. However, a comprehensive and complete research on this issue has not been done yet. In the exploration of exploratory wells, in the world and in Iran, research on the contractual risks of this type of contract and how to allocate these risks has not been done yet, and as a result, a project with this title has not been realized yet.
Engineering
Fater Iorhuna; Abdullahi Muhammad Ayuba; Thomas Aondofa Nyijime; Hussein Muhammmedjamiu
Abstract
In this study, the substance was theoretically examined using computational techniques to provide more analysis on the cytarabine inhibition on the aluminum surface. Through DFT and molecular dynamic simulations, the quantum chemical approach was used to study the parameters. Al (110) surface was chosen ...
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In this study, the substance was theoretically examined using computational techniques to provide more analysis on the cytarabine inhibition on the aluminum surface. Through DFT and molecular dynamic simulations, the quantum chemical approach was used to study the parameters. Al (110) surface was chosen because of the atoms' close proximity and density on the surface. The local and global reactivity, as well as the Fukui function, were computed to determine the molecule's reactivity. The mechanism of cytarabine is assumed to display physiosorption with aluminum surface based on the predicted adsorption and binding energies (-52.476 and 52.476 Kcal/mol) and the negative value of the EHOMO which is -5.133eV. In conclusion, the molecule is described as an efficient aluminum inhibitor having just a mild inhibition on the studied aluminium surface.
Ahmad Keshavarzi
Abstract
One of the infrastructures that can guarantee the economic and technological success of researchers and knowledge-based companies in the age of knowledge is the attention to intellectual property rights. Given that most of the assets of researchers and knowledge-based companies are intellectual property, ...
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One of the infrastructures that can guarantee the economic and technological success of researchers and knowledge-based companies in the age of knowledge is the attention to intellectual property rights. Given that most of the assets of researchers and knowledge-based companies are intellectual property, so the management and legal protection of intellectual property will be inevitable. On the other hand, to enter the world economy, one must be familiar with the specific literature of the business world, one of the key topics of which is intellectual property rights. Therefore, not knowing the issues of intellectual property rights will be a serious threat for researchers and knowledge-based companies and knowing it as a great opportunity. However, today, due to the expansion of communication at national, regional and international levels, especially through the World Wide Web and the ability to quickly and easily access all information and the possibility of some people abusing the works and achievements of others, it has been added.
Basic Medicine
Atefeh Saedi; Saeed Saedi; Mohammad Mehdi Ghaemi; Maryam Milani Fard
Abstract
At the end of 2019, several cases of pneumonia of unknown cause appeared in Wuhan, Hubei Province, China, which quickly spread to other provinces. China In the early stages, it was reported that most patients had a history of contact with Huan seafood. Patients were more likely to have a fever and cough ...
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At the end of 2019, several cases of pneumonia of unknown cause appeared in Wuhan, Hubei Province, China, which quickly spread to other provinces. China In the early stages, it was reported that most patients had a history of contact with Huan seafood. Patients were more likely to have a fever and cough symptoms. The spread of SARS-CoV-2 was very rapid. WHO has declared its prevalence as a public health emergency of international concern. On February 11, 2020, the International Committee for the Classification of Viruses renamed the virus "Acute Respiratory Syndrome of Coronavirus-2 (SARSCoV-2) and WHO SARS-CoV-2 Disease as Coronavirus 2019" (Covid-19 ) Declared an epidemic. The present study is a PICO review study that Epidemiological study of Covid-19 and risk factors. The browsing documents searched in the Google Scholar, Sid and Mag Iran databases were analyzed using the keywords epidemic, covid-19, risk factors. The COVID-19 epidemic has spread very rapidly to several countries, including European countries, Asian countries, the United States, and so on. Most countries, especially developing countries, expanded.
Engineering
Ebadollah Amouzad Mahdiraji
Abstract
Corona electric discharge phenomenon occurs when the electric field intensity exceeds the corona threshold. In the analysis of this paper, three types of hypotheses of partial charge (electrons, positive ions, negative ions) generated in the air due to corona electrical discharge are considered. The ...
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Corona electric discharge phenomenon occurs when the electric field intensity exceeds the corona threshold. In the analysis of this paper, three types of hypotheses of partial charge (electrons, positive ions, negative ions) generated in the air due to corona electrical discharge are considered. The physical process is produced along with the changes and dynamics of the electric charge applied to the field by the charge movement which has velocity due to electric fields and motion due to slope (diffusion) and we will also see losses in electric charge. In this paper, electric load evaluation on a polymer surface by a positive impact corona in the air was performed. Output (circuit current) and input (electric fields and electric charge space density) are considered in computer simulation analysis. Different models have been used to identify the corona, depending on the intensity and extent of the voltage surges. The dynamics and distribution of electric charges and electric fields are analyzed and compared by two models of corona charging (glow and burst impulse).
Physics
M. I. Anthony; O. O. Ige; U. Rilwan; A. M. Hassan; N.U. Angela; Atef El-Taher
Abstract
In this study, the neutron-induced fissile isotopes of Thorium-232 using the Coupled-Channel Optical Model code (OPTMAN) code up to 20 MeV. The high demand for nuclear reactor fuels has necessitated this research. As one of the major naturally occurring radionuclides with lots of fuel prospect, Thorium-232 ...
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In this study, the neutron-induced fissile isotopes of Thorium-232 using the Coupled-Channel Optical Model code (OPTMAN) code up to 20 MeV. The high demand for nuclear reactor fuels has necessitated this research. As one of the major naturally occurring radionuclides with lots of fuel prospect, Thorium-232 occur in 99.98%. Some steps process away from Thorium-232 on neutron capture can produce fissile materials to be used as reactor fuel. Computations were done for both the Potential Expanded by Derivatives (PED) which account for the Rigid-Rotor Model (RRM) that treat nuclei as rigid vibrating sphere as well as account for nuclear volume conservation and Rotational Model Potentials (RMP) which account for the Soft-Rotator Model (SRM) that treat nuclei as soft rotating spherical deformed shapes. Each of the calculated data was compared with the retrieved data from Evaluated Nuclear Dada File (ENDF) which was found to be in good agreement. The threshold energies in all cases were found to be ≤ 4 MeV for both PED (Potential Expanded by Derivatives) and RMP (Rotational Model Potentials). It is observed that results from RMP much better agreed with the retrieved data than one obtained from PED.
Basic Medicine
Saeed Saedi; Atefeh Saedi; Mohammad Mehdi Ghaemi; Maryam Milani Fard
Abstract
Breast cancer is defined as changes in the uncontrolled growth of cells in breast tissue that occur abnormally in the mammary glands (lobules) or in the ducts that connect the lobules to the nipple. The present study is an epidemiological study of breast cancer in Iran. The browsing documents searched ...
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Breast cancer is defined as changes in the uncontrolled growth of cells in breast tissue that occur abnormally in the mammary glands (lobules) or in the ducts that connect the lobules to the nipple. The present study is an epidemiological study of breast cancer in Iran. The browsing documents searched in the Google Scholar, Sid and Mag Iran databases were analyzed using the keywords epidemic, cancer, breast. Based on the results obtained in this study, the incidence and death rate and burden of breast cancer in Iran has risen significantly, compared with previous years. Because of the vital role of women in the family, economy, health, development and other areas, early detection of breast cancer and its prevention according to its high prevalence around the world, as one of the best approaches to control this disease, is important.
Chemistry
Nabil Vaeli
Abstract
In this research, the Oliveria decumbens native and medicinal plant has been used. The extract of this plant contains anti-inflammatory compounds, very strong antioxidants, Allergic reduction compounds and antiviral and anticancer compounds. Extraction of this plant was investigated using supercritical ...
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In this research, the Oliveria decumbens native and medicinal plant has been used. The extract of this plant contains anti-inflammatory compounds, very strong antioxidants, Allergic reduction compounds and antiviral and anticancer compounds. Extraction of this plant was investigated using supercritical extraction system using supercritical CO2 fluid in two stages with ultrasound waves and without ultrasound waves, which the research showed that the highest percentage of effective compounds was extracted by supercritical fluid through the ultrasound process. In this study, the extractive effect of two compounds of Octanoic acid and Nonadecanoic Acid as two compounds with the highest drug effect was investigated due to the anticancer and antiviral properties. This amount for the active substance Octanoic Acid in SCF state is 0.02 and in the USCF is 0.14. and for Nonadecanoic Acid in the SCF state is 0.11 and in the USCF state it is 0.86. Also, the extraction in the supercritical device was investigated in both states with ultrasound and without it, at pressures of 190, 170 and 210 bars and the temperatures of 55,45 and 65 Centigrade and frequencies of 37 and 80 kHz. The results showed that the percentage of product (gram of active ingredient / gram of sample) at the pressure of 210 bar and 37 kHz frequency had the highest extraction rate.
Chemistry
Aliyu Benson; Ayodele Akinterinwa; Charles Milam; Abdulazeez M. Hammed
Abstract
Evaluation of natural resources via chemical profiling is a prerequisite to mining and material sourcing, which are important activities in positioning an economy for the future. This study explores the untapped rocks located within the Bakin Dutse hills in Adamawa State, northeastern Nigeria. The minerals ...
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Evaluation of natural resources via chemical profiling is a prerequisite to mining and material sourcing, which are important activities in positioning an economy for the future. This study explores the untapped rocks located within the Bakin Dutse hills in Adamawa State, northeastern Nigeria. The minerals and elemental compositions of the rock samples were determined using X-ray diffractometer (XRD) and X-ray fluorescence (XRF) instruments respectively. Results of the mineral composition of the rock samples showed (in order of abundance) the presence of quartz, albite, annite, and microcline, as well as orthoclase, phlogopite, oligoclase, chrysotile, and cordierite which were sparsely found in the study area. The abundant presence of silicate and aluminum silicate minerals in the study area was also shown in the major elemental composition of the rock samples, which follow the order SiO2 (55.76 – 63.81%) > Al2O3 (11.06 - 13.15%) > Fe2O3 (8.41 – 11.2%) > K2O (6.12 – 7.75%) > CaO (2.29 – 6.37%) > Na2O (2.4%) > MgO (0.09 -2.2%) > SO3 (0.37 – 1.05%). The minor elements in the rocks include PbO, TiO2, BaO, CuO, ZnO, P2O5, ZrO2, Rb2O, MnO, and Cl. The mineral and elemental compositions of the soil in the study area show similarities that link the origin of the soil to the weathering of the rocks. The geo-chemical data provided in this study will make an important contribution to both the literature and the database for future mining prospects in the study area.
Engineering
Marzieh Samimi
Abstract
Energy carriers as one of the important inputs of production as well as consumer goods of households, play a very important role in determining production costs and household expenditures. Price fluctuations in each of these carriers will cause fluctuations in production costs, consumer spending, and ...
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Energy carriers as one of the important inputs of production as well as consumer goods of households, play a very important role in determining production costs and household expenditures. Price fluctuations in each of these carriers will cause fluctuations in production costs, consumer spending, and ultimately inflation. The extent of this fluctuation, depending on the importance and share of each carrier, can be examined in the total basket or in the issues of production and consumption. These oscillations can be divided into two parts: "direct load" and "indirect psychological load". Indirect psychological burden shapes the expectations of households and producers, and direct burden reflects the direct impact of price fluctuations. Statistics show that the relative price of energy carriers is lower than the price of other domestically produced goods or energy prices in the region and the world, and this gap between the price of domestic energy carriers compared to world prices has led to its growth over the last decade Accelerate and increase the share of carrier costs in the total consumer basket. Identify the gap between the mentioned variables, the mechanism of presenting corrective or supportive, and institutional policies to reduce the possible negative consequences and put the economy on the path of increasing the efficiency of production factors. This article examines the challenges of managing the consumption of energy carriers in Iran.
Physics
Mohammad Ranjbarian
Abstract
The purpose of this study is to evaluate the excellence of Ilam Telecommunication Organization based on EFQM. The statistical population of this research is all the personnel of Ilam Telecommunication Organization and the sample size has been obtained using Cochran's formula of 202 people. Data collection ...
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The purpose of this study is to evaluate the excellence of Ilam Telecommunication Organization based on EFQM. The statistical population of this research is all the personnel of Ilam Telecommunication Organization and the sample size has been obtained using Cochran's formula of 202 people. Data collection tool in this study was a questionnaire, the validity of which was confirmed and its reliability was obtained through Cronbach's alpha coefficient of 89%. In this research, library and field methods have been used to collect information, and the present research is applied in terms of purpose and based on how to obtain the required data of descriptive research to analyze the data of the questionnaire in Descriptive statistics section (mean, standard deviation, ...) and inferential statistics section (pattern determination test, test of research hypotheses through means comparison test, one-sample t-test) have been used in SPSS software package. In this research, an attempt has been made to examine the situation of the employees of the Telecommunication Organization of Ilam Province based on the nine areas mentioned in the two groups of results and enablers. Finally, after performing the final analysis and using the test related to the hypotheses and using the one-sample t-test, it was determined that the population considered in this study, i.e. the employees of the Telecommunication Organization of Ilam province, has obtained 514 points out of 1000. All hypotheses are accepted and finally suggestions for each criterion are presented for continuous improvement.
Physics
Ateeq ul Rehman; Tahir Munir; Shahbaz Afzal; Muhammad Saleem; Imosobomeh L Ikhioya
Abstract
Recent successes in the development of lead (Pb) halide perovskites have urged extensive research into cost-effective photovoltaic devices, to avoid significant challenges related to stability and toxicity. In this study, device modeling was presented for lead (Pb)-free perovskite solar cells (PSC), ...
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Recent successes in the development of lead (Pb) halide perovskites have urged extensive research into cost-effective photovoltaic devices, to avoid significant challenges related to stability and toxicity. In this study, device modeling was presented for lead (Pb)-free perovskite solar cells (PSC), by employing FAsnI3 as the perovskite absorber layer. The simulation evaluates the impact of varying thickness, acceptor density of the hole transport layer (HTL), and temperature within the ranges from 50 to 250 nm, 1x1018 cm-3 to 1x1022 cm-3, and 300 K to 450 K, respectively. The photovoltaic cell has inverted geometry (p-i-n) and device structure is ITO/PEDOT:PSS/FASnI3/BCP/Au. The FASnI3-based PSC exhibits an efficiency of 14.03%, current density (Jsc) 20.4 mA/cm2, fill factor (FF) 76.7%, and open circuit voltage (Voc) 0.92 V and these results are already presented experimental with same device structure. These results showed that a more eco-friendly solar cell using methyl ammonium tin was created successfully as perovskite. It is suggested to use alternative materials instead of methyl ammonium tin as perovskite.
Clinical Medicine
Ali Maher; Leila Mehrdana; Mehrnoosh Jafari
Abstract
The present study is descriptive in terms of applied purpose. The statistical population of this study includes the staff (supervisors, head nurses, staffs of wards) of private hospitals in Tehran, including 140 people, by using Morgan table, 100 of these people were selected in the mentioned hospitals ...
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The present study is descriptive in terms of applied purpose. The statistical population of this study includes the staff (supervisors, head nurses, staffs of wards) of private hospitals in Tehran, including 140 people, by using Morgan table, 100 of these people were selected in the mentioned hospitals and by using cluster random sampling method, five hospitals were selected as a sample. In this study, a questionnaire with Likert spectrum and fuzzy analytical network process was used to perform pairwise comparisons. The average Cronbach''s alpha coefficients were calculated above 0.8, which indicates that the opinions are reliable and have good reliability. According to the analytic hierarchy process and prioritization of criteria, it can be seen that "proper use of medical and non-medical consumables (S)" has the highest rank with a final weight of 0.107065 and "supervision of department warehouses and their organization (W)" with the final weight of "0.00559g" has the lowest rank of the factors related to reducing the cost of private hospitals in Tehran. The results of the study showed that the majority of units in the studied hospitals had operational losses despite their high capacity. In many of the studied units, there was a significant discrepancy between the number of services provided and the amount of services required to locate the operational center at the head point, and these factors impose a financial burden on the studied hospitals.
Basic Medicine
Ronak Rahimiyan
Abstract
Network methods are one of the most widely used groundwater modeling tools that have become widespread and popular in the last two decades. On the other hand, advances in the computing power of computers and their ease of access have led to the rapid development of numerical methods for solving groundwater ...
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Network methods are one of the most widely used groundwater modeling tools that have become widespread and popular in the last two decades. On the other hand, advances in the computing power of computers and their ease of access have led to the rapid development of numerical methods for solving groundwater problems. In this study, with a new approach to network methods, these methods are introduced as a numerical model to simulate the movement of groundwater. The first step in estimating groundwater behavior is to obtain a mathematical model. According to Darcy's law and the establishment of mass conservation, it can be shown that the equation governing groundwater in stable conditions is the Laplace equation. Therefore, by obtaining the physical properties of the desired aquifer using the experiment and understanding the boundary conditions governing that aquifer, a complete mathematical model governing the desired problem can be obtained. Unfortunately, since the physical properties of the problems in nature are not homogeneous and the boundaries of the problems under study are geometrically irregular, it is impossible to solve these problems analytically. To do so, researchers have been using numerical and laboratory methods for years. All numerical methods for solving the Laplace equation first decompose the scope of the problem in the sense that they either divide it into multiple nodes or into multiple elements and then use mathematical methods. In this article, a new approach is to find algebraic relations between those different nodes or elements. In other words, after parsing the scope of the problem, they turn the Laplace equation into a system of linear equations.
Chemistry
Samuel N. Ndung’u; Ruth N. Wanjau; Esther W. Nthiga
Abstract
The current study utilizes Silicon Nitride (Si3N4) as a novel adsorbent in evaluating its adsorptive ability for Congo red dyes from an aqueous solution. The adsorbent was prepared using extracted silica from sand and coffee husk biochar in an ammonia environment. The Si3N4 adsorbent was characterized ...
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The current study utilizes Silicon Nitride (Si3N4) as a novel adsorbent in evaluating its adsorptive ability for Congo red dyes from an aqueous solution. The adsorbent was prepared using extracted silica from sand and coffee husk biochar in an ammonia environment. The Si3N4 adsorbent was characterized using a Field Emission Scanning Electron Microscope (FEI ESEM) which showed rod-like and fiber-like structures for α-Si3N4 and β- Si3N4, respectively. The SEM results also showed pores on the adsorbent surface before adsorption and a more rigid and restrained surface after adsorption. The adsorbent surface is hydroxylated in water to give important adsorption sites of silanolate ions (Si-O-) and silazane groups (Si2=NH2+) responsible for congo red (CR) dye removal. The adsorption process was investigated by batch mode. The maximum adsorption capacity (28.87 mg/g) was obtained at an optimal pH=1.00, agitation time (50 minutes), adsorbent dosage (25 mg), and initial concentration (50 mg/L). The Langmuir isotherm model was best fitted with equilibrium data with R2 > 0.9, showing that the adsorption was chemisorption in nature. The results revealed Si3N4 adsorbent as a potential adsorbent in textile dye wastewater treatment.
Clinical Medicine
Aslan Ahmadi; Hadi Ghanbari; Mohammad Mehdi Salem; Amir Mohammad Milani Fard; Khosro Barkhordari
Abstract
Background: Due to the lack of interventional studies on the change in sound quality of patients suffering laryngeal cancer after partial frontolateral laryngectomy and anterior TVC reconstruction using laser, we aimed to assess the extent of changes in sound quality after correction of anterior vocal ...
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Background: Due to the lack of interventional studies on the change in sound quality of patients suffering laryngeal cancer after partial frontolateral laryngectomy and anterior TVC reconstruction using laser, we aimed to assess the extent of changes in sound quality after correction of anterior vocal cord web by flap technique using TVC base in frontolateral laryngectomy by voice handicap index (VHI) and voice analysis factors in patients with glottic cancer.Methods: In this interventional case series study, 15 consecutive patients with laryngeal carcinoma undergoing partial frontolateral laryngectomy by laser at Hazrat Rasool Akram Hospital between 2017 and 2019 suffering anterior adhesion of vocal cords were entered in final evaluation. All patients underwent microlaryngeal flap surgery to improve sound quality. The anterior web of larynx was dissected with a 6-watt super pulse CO2 laser. Results: The vocal analysis before and after operation showed a significantly improving vocal quality parameters including Habitual F0, Jitter, Shimmer, Tremor F0, Mean F0, SD F0, Max F0, NNE, HNR, SNR, Ratio, Hoarse score, Harsh, and breathy after surgery as compared to before that. The scores for three emotional, physical, and functional components of VHI all significantly improved after operation. Conclusion: The correction of anterior vocal cord web by flap technique using TVC base in frontolateral laryngectomy leads to favorable outcome regarding vocal quality and voice performance in patients suffering glottic cancer
Engineering
Mohadeseh Aliakbari
Abstract
In this study, knowledge management in commercial companies has been studied. In an age where knowledge determines the power and wealth of societies, knowledge management and transfer has become the most important task of societies and organizations within them. Organizations that effectively acquire, ...
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In this study, knowledge management in commercial companies has been studied. In an age where knowledge determines the power and wealth of societies, knowledge management and transfer has become the most important task of societies and organizations within them. Organizations that effectively acquire, create, transfer and use knowledge to improve and improve they do their activities and functions. An organization without knowledge cannot organize itself and survive as a living and dynamic military. Organizations are determined to acquire knowledge and use it. Managers who make tough decisions are more likely to seek out experienced people than to constantly expose their knowledge to decisions instead of searching for information in databases. According to studies, managers obtain two-thirds of their information and knowledge by referring to writings and documents (Davenport, 2000). Moves and promotes the knowledge of organizations and is one of the important factors in empowerment. Build organizations to compete in the supply of the new global economy. Today, organizations are in dire need of increasing quality, value, service and speed in order to be able to expand in the market, and this trend will certainly become more important in the future and will be considered as the biggest organizational competitive advantage in the global economy.
Clinical Medicine
Roohallah Yousefi
Abstract
In summary, this study investigated the relationship between climate, COVID-19 transmission and mortality rates. The results showed that countries with colder climates have higher infection and mortality rates. This could be due to factors such as increased time spent indoors during the winter and less ...
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In summary, this study investigated the relationship between climate, COVID-19 transmission and mortality rates. The results showed that countries with colder climates have higher infection and mortality rates. This could be due to factors such as increased time spent indoors during the winter and less outdoor activity in cold conditions. On the other hand, warmer temperatures and higher humidity were associated with lower transmission rates of COVID-19. In contrast, colder temperatures and lower humidity may favor the spread of the virus. In addition, air pollution was found to worsen COVID-19 transmission and mortality rates, possibly due to its effects on respiratory health and immune function. These findings highlight the complicated relationship between climate, air pollution, COVID-19 transmission, and mortality rates. We also point out that various factors must be taken into account to understand the COVID-19 dynamics in different climatic and environmental conditions.
Engineering
Masoud Mahdavi; Seyyed Reza Hosseini; Abbas Babaafjaei
Abstract
The seismic performance of a steel structure depends on various factors, such as the design, materials, and dimensions. One important aspect to consider is the span length of the structure, which can influence the seismic response and the overall performance of the structure. In this study, a 10-story ...
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The seismic performance of a steel structure depends on various factors, such as the design, materials, and dimensions. One important aspect to consider is the span length of the structure, which can influence the seismic response and the overall performance of the structure. In this study, a 10-story steel structure with chevron bracing system was designed with ABAQUS software and finite element method. The structure was subjected to the El Centro earthquake for 25 seconds using the dynamic analysis method. Furthermore, the W index was defined equal to the span length to the story height, and the values of 0.67, 1.67, and 2.5 were considered for W. The results showed that the increase of the W index has direct relationship with the changes in the seismic parameters of the structure, including the displacement and acceleration, the von mises stress, the acceleration-time, and the displacement-time diagrams in the roof and the base shear force. Changing the index from 0.67 to 1.67 and 2.5 has caused an increase of 13.34% and 16.67%, respectively. Changing the index from 0.67 to 1.67 and 2.5 has caused an increase of 10.15% and 52.28%, respectively. Changing the index from 0.67 to 1.67 and 2.5 has caused an increase of 43.75% and 109.37%, respectively. Changing the index from 0.67 to 1.67 and 2.5 has caused an increase of 20.83% and 47.91%, respectively.
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